Objective To evaluate the role of contrast-enhanced color Doppler ultrasonography with Levovist in the diagnosis of liver tumors.Methods One hundred and twenty-five patients with 126 hepatic solid lesions were examined by conventional color Doppler and contrast enhanced ultrasonography.All hepatic lesions were confirmed by pathology.Of these,79 cases with hepatocellular carcinoma,4 cases with metastatic liver carcinoma,13 cases with hemangioma,7 cases with inflammatory pseudotumor of liver,7 cases with focal nodule hyperplasia,and 15 cases with other benign lesions.The Levovist with a concentration of 400 mg/ml was injected into an antecubital vein within approximately 2 minutes.Results All hepatic solid lesions with blood supply were differently enhanced by contrast-ultrasonography (I～IV grades).The color flow signals with grade III and grade IV were detected in one malignant lesion before contrast-enhancement and in 41 malignant lesions ( 49.4%) after contrast-enhancement.The color flow signals were detected by contrast-enhanced sonography in 26 malignant lesions ( 92.8%) with no color Doppler signals and in 33 benign lesions ( 76.7%).The mean resistive index of liver cancer group was much higher than that of benign lesion group before and after contrast-enhancement.The accuracy rate for diagnosing liver tumors was raised from 66.7% (84/126) in pre-enhancement to 94.4% (119/126) in post-enhancement.Conclusions The contrast-enhanced color Doppler ultrasonography is very useful in the differential diagnosis of liver tumors.

Objective To evaluate the feasibility of virtual touch tissue quantification (VTQ) for the assessment of renal allograft.Methods A total of 72 kidney recipients were examined with conventional ultrasound and VTQ after transpantation.Biopsies were performed in 34 patients,20 patients were with acute rejection (AR),14 with chronic allograft nephropathy (CAN),38 patients as control group.The peak systolic velocity (PSV) and resistance index(RI) were measured on main,infrarenal and arcuate arteries with conventional ultrasound and shear wave velocity (SWV) of the renal cortex was obtained by VTQ.All the data were compared among three groups.Results There were no significant differences of PSV between two groups.An increased RI was presented in the CAN group(P ＜0.05).The mean SWV was (2.67 ± 0.27) m/s,(2.90 ± 0.31)m/s and (2.28 ± 0.24)m/s for AR,CAN and normal group,respectively.There were significant differences of SWV among the three groups (P ＜ 0.05).Conclusions VTQ technique could provide a new method for the assessment of transplanted kidney.

Objective To probe the correlation between the short-axis diameter(SD) of coagulation necosis and the microwave power(P) using a new type of internally cooled microwave antenna in ex vivo and in vivo liver model.Methods Fourteen microwave ablations were performed in swine livers ex vivo and canine livers in vivo under the microwave powers of 30-90W and the durations of 10 min and 20 min, respectively.The short-axis diameter(SD) and the long-axis diameter(LD) of the coagulation were measured.The difference of SD, LD and SD/LD in swine liver ex vivo and canine liver in vivo were compared.The relationship between the SD and microwave power was analysised using linear regression model.Results Under the same conditions,the SDs and LDs of the coagulations of canine livers in vivo were smaller than those of swine livers in ex vivo (P <0.01).There was such a higher linear relationship(r = 0.96-0.99, P <0.01) between the SD of coagulation and the power in vivo liver model as the results acquired in ex vivo.Conclusions Although the blood flow decreased the SDs of the coagulation of microwave ablation in liver in vivo, but there was still a higher linear relationship between SD and microwave power.

Objective To probe the correlation between the short-axis diameter(SD) of microwave coagulation and the time(T) and/or power(P) using a new type of internally cooled microwave antenna. Methods A MTC-3 microwave apparatus with a new type of internally-cooled microwave antenna was used to coagulate a fresh porcine liver in vitro. The correlation was analyzed between the SD of coagulation necrosis and the time and/or power. Results ①Under the same power, there was high linear relationship(r= 0.94- 0.98,P

Objective To compare features between color Doppler flow imaging(CDFI) and contrast-enhanced ultrasonography(CEUS) in the diagnosis of small renal cell carcinoma(SRCC) and investigate the diagnostic value of CEUS. Methods The images of CDFI and CEUS examination were retrospectively analyzed in forty-five SRCC (≤3 cm in diameter) which were confirmed sequentially by operation and pathology. Inner echoes,boundary,dark-ring and color flow of tumors were observed by CDFI. The degree of tumor vascularity was subjectively graded from 0 to Ⅳ. Enhancement patterns and phases on uhrasonography were reviewed, including enhancement start time, peak time, wash-out time and enhancement appearances of SRCC. Results The images were observed as homogeneous or relatively homogeneous (19) and heterogeneous or relatively heterogeneous(26), clear boundaries(37, including 10 with dark-ring) and ill-defined margins(8). The tumor vascularity was showed as grade 0(5) ,grade Ⅰ (6),grade Ⅱ (14),grade Ⅲ (14),grade Ⅳ(6) on CDFI. All lesions were showed mean enhancement start time (13.84±3.80) seconds,peak time (19.49±4.73) seconds,wash-out time (26.91±5.86) seconds respectively on CEUS. All cases were observed as simultaneous wash-in(39) and gradually wash-in(6),hyperechoic(14) and isoechoic(22) and hypoechoic(9) in peak time, simultaneous wash-out (19) and rapidly wahs-out (19) and gradually wahs-out(7). After contrast medium injection, tumors were detected partly non-enhaneement or cellular enhancement (25) and pseudocapsule (20). Conclusions CEUS is effective in improving the sonographic visualization of tumoral vascularity ,internal structure and pseudocapsule. It plays an important role in the diagnosis of SRCC.

Objective To study the value of quantitative analysis of contrast-enhanced ultrasound in diagnosing acute rejection of kidney graft.Methods Sixty-seven patients with normal kidney grafts and thirty-five patients with acute rejection were recruited.In conventional ultrasound,the peak systolic velocity (PSV) and resistance index (RI) of segmental artery and interlobar artery were measured.In quantitative analysis of contrast-enhanced ultrasound,four regions of interest including renal cortex,medulla,segmental artery and interlobar artery were drew and three parameters including rising time(RT),time to peak(TTP) and mean transit time(mTT) were obtained.In addition,the difference in RT,TTP and mTT between the renal cortex and interlobar artery,as well as medulla and interlobar artery were calculated.Results The differences of PSV in interlobar artery between the two groups were statistically significant (P ＜0.05).The time-intensity curves of the whole kidney grafts,and the difference in RT and TTP between the renal cortex and interlobar artery were statistically different between two groups (P ＜0.05).Conclasions Quantitative analysis of contrast-enhanced ultrasound proved a quantitative method for diagnosing kidney allograft acute rejection.

Objective To investigate the viability of virtual touch tissue quantification (VTQ)technique in the prediction of acute rejection in transplanted liver.Methods One hundred and eighteen patients enrolled in the study were categorized into four groups:normal control (n =31),cirrhosis ( n =29),transplanted liver with acute rejection (n =28),transplant liver without any complications (n =30).All the patients were confirmed by pathology or clinical results.The VTQ of right robe of liver was obtained by a ultrasound system with VTQ technique and the data was compared among the four groups.Results The VTQ was (1.10 ± 0.29)m/s,(1.33 ± 0.33) m/s,(1.81 ± 0.47) m/s and (2.12 ± 0.59) m/s in normal control,transplanted liver without any complications,transplanted liver with acute rejection and cirrhosis group,respectively.It was significantly different in all four groups (P＜0.01).Patients with acute rejection were associated with the increase of the VTQ values (P＜0.01).Using a cutoff of VTQ＞1.36 m/s measured in the transplanted liver for prediction of acute rejection,the sensitivity and specificity were 82.1％ and 68.2％.Conclusions VTQ technique may have some clinical value in evaluation the acute rejection in transplanted liver.

Objective To evaluate the diagnostic value of virtual touch tissue quantification (VTQ) in the diagnosis of renal allograft fibrosis.Methods The renal allografts of 82 patients with biopsies or nephrectomy were assessed by virtual touch quantification.The renal allograft fibrosis was categorized according to the 2005 updated Banff criteria for a G0～G3 grade.All the results were compared among four groups.Results The mean SWV values in G0～G3 were (2.39 ± 0.31)m/s,(2.45 ± 0.34)m/s,(2.58 ± 0.18) m/s,(3.11 ± 0.40)m/s,respectively.There were no significant differences in the mean SWV value between G0 and G1 group,or between G1 and G2 group(P ＞0.05).There were significant differences in the mean SWV value between G0～G2 and G3 group,or between G0 and G2 group(P ＜0.05).Stiffness of renal allograft was significantly correlated to the mean SWV value (Spearman r =0.671,P ＜0.001).According to the area under the ROC curve,the sensitivity and specificity of SWV (area under ROC curve =0.847,cut-off=2.64 m/s) for grade ≥G2 was 78.9％ and 79.5％ respectively.Conclusions Stiffness measured by VTQ reflects the interstitial fibrosis in renal allograft.VTQ technique might be a new tool to identify patients with chronic allograft injury.

Objective To compare enhancement features of primary hepatocellular carcinoma(PHCC)and recurrent hepatocellular carcinoma(RHCC) on.contrast-enhanced ultrasonography(CEUS). Methods CEUS was performed in 56 patients with 70 RHCC and 83 patients with 93 PHCC. The enhancement features of these two groups of hepatocellular carcinoma were compared. The time used for the enhancement material to arrive the lesion(Ta ), that used for the lesion to become isoechoic(T1 ) and hypoechoic relative to the surrounding hepatic parenchyma(To) were analyzed. The echogenicity change between the lesion and the parenchyma was observed during arterial phase,portal phase and delayed phase. Results The time used for the lesion to become hypoechogenicity of RHCC and PHCC was (104.0 ± 51.8)s, (85.5 ± 43.0)srespectively,there was significant difference between the two groups( P = 0.010). There were 24 (34.3 % )cases of RHCC and 16 ( 17.2% ) cases of PHCC becoming isoechoic during portal phase,the former rate was significantly higher than the later one( P = 0. 012). Conclusions There is significant difference between PHCC and RHCC in the performance of CEUS,this is useful for the early diagnosis of RHCC.

Objective To investigate the viability of analysis of hemodynamic changes with color Doppler flow imaging in the prediction of acute rejection in transplanted liver.Methods Sixty-eight patients enrolled in the study were categorized into three groups:transplanted liver without acute rejection [rejection activity index(RAI) 0-3,n =24],transplanted liver with mild acute rejection (RAI 4-5,n =23),transplanted liver with moderate and severe acute rejection (RAI 6-9,n =21).All the patients were confirmed by pathology.The color Doppler flow imaging were performed in all the patients within 24 hours and 1 week after biopsy.Results In transplanted liver with moderate and severe acute rejection,the peak systolic velocity of portal vein (PV-PSV) was (31.4 ± 14.1)cm/s,significantly lower than that in transplanted liver without acute rejection,which was (45.1 ± 17.7)cm/s (P ＜0.05).A week later after steroid therapy,the PV-PSV in transplanted liver with moderate and severe rejection was increased to (46.7 ± 21.8)cm/s(P ＜0.05).Patients with acute rejection were associated with the decrease of the PVPSV (P ＜0.05).Conclusions The decrease of PV-PSV may have some clinical value in evaluation the acute rejection in transplanted liver.